The rise of high-performance multi-rotor unmanned aerial vehicles-how worried should we be?

High-performance multirotor drones optimised
for speed and agility present a significant and increasing
challenge to current counter-drone systems based on jamming
or physical interdiction. Existing jamming technology requires
sustained visual line of sight targets and is most effective
in countering threats from relatively slow and RF compliant
videography drones. Physical interdiction using nets is again
only suitable for low-speed interception. Small vehicles based
on commercially available consumer drone technology with a
mass of less than 1 kg and package size of 15 cm can achieve
flight speeds in excess of 70 m/s and can accelerate at up to 15g,
and are sufficiently inexpensive as to be considered disposable.
Custom flight control systems bypass geofence restrictions and
the wide availability of high power radio links greatly exceeding
OFCOM limits significantly reduces the range over which
commercial jamming systems are effective. Static acceleration
performance is maximised simply by decreasing the power
loading and decreasing the disc loading and is approximately
independent of the size (mass) of the vehicle. Maximisation
of top speed is more complex, requiring identification of an
optimal disc loading that balances thrust against rotor drag.
Top speed is also affected by area/volume scaling meaning that
larger vehicles with the same power to weight ratio and disc
loading generally have less drag and hence higher top speed.
Consumer technology for very high thrust to weight ratio
variants of larger multirotor drones is currently not readily
available. However, 10 kg drones with a top speed of 100 m/s
and static acceleration of 20 g are foreseeable in the next 5
years.